Formycin triphosphate is a fluorescent analog of ATP, exhibiting enhanced fluorescence when binding to enzyme active sites. It acts as a competitive inhibitor of avian liver pyruvate carboxylase (pyruvate carboxylase). Additionally, formycin triphosphate increases atrial natriuretic factor (ANF)-stimulated guanylate cyclase activity with an EC50 of approximately 90 μM and inhibits ATP-stimulated guanylate cyclase activity with an IC50 of around 100 μM.